It is a common custom to open the lid of a can containing powdered milk and scoop some powder with a spoon and then put it into a milk bottle, when we want to dissolve powdered milk for feeding a body. Because the lid of can is often opened, the milk is likely to be contaminated. Besides, it may not be easy to put powdered milk in a bottle with a spoon, as the bottle generally has a small mouth and some of the powdered milk may be spilled outside of the bottle. If the spoon is wet, the milk will stick to it. These are quite inconvenient for the user, and not good from the sanitary point of view.